Considering the US is also ramping up their "Cyber defense force" then sure, I think it would be a plausible reaction. The Chinese are using the data that they steal to either improve their own manufacturing facilities or learn the weaknesses in the designs to better attack the vehicles and systems. Of course they deny any of this actual activity. Unless solid evidence can be linked back to the Chinese goverment, then it is tough to get the UN to intervene. Its kinda like the world's worst kept secret.

The problem the US faces is filling the seats with talented individuals who can combat the enemy who have little problem in getting their seats filled. US doesn't pay enough nor is it easy to find someone with a top secret clearance who is out of work.

I doubt the US would pull the trigger on a full blown cyber war except for very specialty, tactical operations. Even then they'd go out of their way to prevent escalating with an entity like China that has a fully operational cyber warfare capability. Remember, the US is in an awkward position. We have possibly (probably) the most powerful cyber weapon platforms in the world, but we are also, by far, the most susceptible to cyber attacks. China would be thrilled to go toe-to-toe with us in a cyber war because at the end of the day the majority of their population can still walk out the front door and farm. The US is the exact opposite. If a cyber strike took out power, supply chains, etc then the majority of our population would die of starvation in a week. It is asymmetric warfare in spades.

I lived in China for 2 years, and I promise, China has just about as much to lose from a cyberwar as the U.S. Where China is at the advantage is they have much more to gain from the slow and low attacks we've seen so far. The U.S. by far has the most intellectual property to lose.

Don't think for a second, though, that farming is a way of life in China. If the cities became uninhabitable, China would have a much bigger problem than the U.S. would. It wouldn't be pretty in either place, though.